/*
 * Copyright (c) 2008, 2016, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the Classpath exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * questions.
 */

package com.sun.btrace.runtime.instr;

import com.sun.btrace.org.objectweb.asm.*;
import com.sun.btrace.runtime.MethodInstrumentorHelper;


/**
 * This visitor helps in inserting code whenever a source
 * line is reached. The code to insert on line number may
 * be decided by  derived class. By default, this class
 * inserts code to print the line.
 *
 * @author A. Sundararajan
 */
public class LineNumberInstrumentor extends MethodInstrumentor {
    private int lastLine;

    public LineNumberInstrumentor(ClassLoader cl, MethodVisitor mv, MethodInstrumentorHelper mHelper,
                                    String parentClz, String superClz, int access, String name, String desc) {
        super(cl, mv, mHelper, parentClz, superClz, access, name, desc);
    }

    @Override
    public void visitLineNumber(int line, Label start) {
        if (lastLine != 0) {
            onAfterLine(line - 1);
        }
        onBeforeLine(line);
        lastLine = line;
        super.visitLineNumber(line, start);
    }

    protected void onBeforeLine(int line) {
        asm.println("before line " + line);
    }

    protected void onAfterLine(int line) {
        asm.println("after line " + line);
    }
}